AMERICA'S
57 - the Ultras

57 Summits with Prominence of 5,000
feet or more (lower 48)

New Elevations added by Aaron Maizlish, 2005.
Accompanying map shows
location of all summits.
This list is reprinted with permission from Andy Martin's County High Points,
available from the author for $15 ppd.

FOOTNOTES:
NEW ELEVATION: All of the elevations that we grew up with, those
that still appear on the USGS 7.5' maps, are outmoded.
Substantial advances in geodesy (the scientific measurement of the
earth's shape) have rendered obsolete the vertical datum on which they
were based. "New Elevations" in this table improve on
existing elevations in two ways: 1. The NAVD88 elevations
have been applied. NAVD88 is the newer vertical datum for North
America that is compatible with commercial GPS units. 2. I
have added footage to mountains in the frequent instance where the
benchmark (published) elevation is known to fall short of the true
summit. More detailed notes on both of these adjustments will
appear in a future article in the theory section of this website.
Virtually all new elevations will range between -5' and +15'.

OLD ELEVATION: The "New Elevations" may be interesting in their
own right, but they aren't useful for prominence calculations.
This is simply because all of our saddle data is based on topographic
maps that used the older, NGVD29, vertical datum. Since
prominence is a measurement of the difference between two values, it
will be more accurate to compare apples and apples.

MOUNTAINS:

Six digit codes in the footnotes section refer to the benchmark PIDs
that reference the summit on the National Geodetic Survey website.[1] Rainier: Summit reference is a
definitive GPS survey published in Point
of Beginning, 2000. The key saddle is in the
town of Armstrong, BC. The 1:50,000 DEM for BC gives the saddle a
low value of 359m (1,178'). According to Robin Tivy, the 1:50,000
Canadian map puts the KS between 360m and 380m. Therefore a new
saddle value of 370m (1,214') has been assumed pending further
investigation.

[2] Whitney: The USGS 7.5' provisional map
gives a value of 14,491'. This was in error, likely based on the
reading of a benchmark that was not on the true summit. The old
elevation value for Mt. Whitney was 14,494' and then 14,495'. The
NAVD88 value for the highest benchmark, TQ0506, is 14,505'.[6] San Jacinto: The 7.5' quad
elevation of 10,804'
is erroneous. The correct NGVD29 elevation should have been
10,831'. In addition the benchmark rests 8' below the natural
summit for a total elevation of 10,839'. The newer NAVD88
elevation is 10,834'+8'=10,842'.[24] Washington: The Key Saddle is on the
Champlain Canal near Hudson Falls, New York, 43º18'59"N,
73º31'46"W. Note that the prominence and saddle elevation
were corrected 3/13/2005.

[27] Borah: See also the Americas
Roof report on Borah that explores the rumor that Borah gained 7'
elevation in a 1983 7.0 earthquake. The NGS benchmark PID is
PZ0770 "Beauty Reset".